DomainKeys Identified Mail, or DKIM, is an email authentication standard that helps receiving mail servers verify that an email truly came from the domain it claims to come from. It works through public key cryptography. The sending mail server signs outgoing messages with a private key. The receiving server then looks up the corresponding public key in the domain’s DNS records to check the signature. This prevents email spoofing and protects your domain from being used in phishing attacks.

Our DKIM Checker tool lets you verify your DKIM records quickly and without any login. You can check a single selector or scan multiple common selectors automatically. The tool also checks your SPF and DMARC records, giving you a complete picture of your email authentication setup.

DKIM Record Checker

Verify DKIM records for your domain. Check key strength, validate selectors, and ensure email authentication compliance.

What is DKIM checker tool

This tool performs a DNS lookup for your domain’s DKIM public key record. It then parses the record, checks the key strength, validates all required tags, and gives you a clear score and grade. You get detailed information about your key length, hash algorithm, and any flags or issues with your configuration.

The tool also checks your SPF and DMARC records. These three protocols work together to protect your email deliverability and domain reputation. When all three are configured correctly, your emails are far less likely to land in spam folders.

Key Features

Single record lookup
Enter any domain and DKIM selector to retrieve and analyze one DKIM record instantly.

Multi-selector scanning
The tool automatically tests your domain against dozens of common DKIM selectors. This helps you discover active selectors you might have forgotten about or legacy keys still published in DNS.

Key strength analysis
The tool extracts your public key from the DKIM record and determines its bit length. Keys of 2048 bits or more are considered secure. Shorter keys receive warnings or recommendations to upgrade.

Complete tag parsing
The tool parses all DKIM tags according to the RFC 6376 standard. You can see the version, key type, public key, hash algorithm, flags, and service type.

SPF and DMARC integration
The tool automatically checks for SPF and DMARC records alongside your DKIM check. This gives you a complete view of your email authentication status.

Export and share results
You can copy the results to your clipboard, export them as a JSON file, or share a deep link with your team.

No login required
The tool is completely free and open to everyone. You do not need to create an account or provide any personal information.

How to Use the DKIM Checker

Using the dkim record checker tool is straightforward.

Step 1: Enter your domain
Type your domain name into the Domain field. Use the format example.com without the http:// or www prefix.

Step 2: Enter your DKIM selector
Type your DKIM selector into the Selector field. The selector is the s= value from the DKIM-Signature header in your outgoing emails. Common selectors include default, google, selector1, and selector2.

If you do not know your selector, you can click the “Scan Common Selectors” button instead. The tool will test your domain against a list of frequently used selectors.

Step 3: Run the check
Click the “Check DKIM” button to check a single selector. Click “Scan Common Selectors” to test multiple selectors automatically.

Step 4: Review your results
The tool displays a summary with a status badge, a letter grade, and a numerical score. It lists any issues found, warnings, and actionable recommendations. Below the summary, you can see each DKIM record found with details about key strength, hash algorithm, flags, and service type. The tool also shows whether SPF and DMARC records are present.

Frequently Asked Questions

What is a DKIM selector and where do I find it?
A DKIM selector is a unique string that identifies which public key to use for a given email. It is the s= value in the DKIM-Signature header of an email. To find it, open an email sent from your domain and view the full headers. Look for the DKIM-Signature header and find the s= tag. Common selectors include default, google, selector1, and selector2.

What do the DKIM tags mean?
The DKIM record is a TXT record in your DNS that contains several tag-value pairs separated by semicolons. The v tag specifies the DKIM version and must be DKIM1. The k tag indicates the key type, usually rsa. The p tag contains the Base64‑encoded public key and is required. The h tag lists the hash algorithms used for signing. The t tag sets flags like test mode or strict mode. The s tag specifies the service type.

What key length should I use for DKIM?
A 2048‑bit RSA key is the current recommendation. Keys of 1024 bits are still acceptable but less secure. Keys of 512 bits or shorter are weak and should be replaced immediately.

Why do I need SPF and DMARC as well?
SPF, DKIM, and DMARC are the three core email authentication protocols. SPF specifies which mail servers are authorized to send email for your domain. DKIM adds a cryptographic signature to each message. DMARC tells receiving servers what to do when SPF or DKIM checks fail. All three work together to protect your domain from spoofing and improve deliverability.

What does it mean if my DKIM check shows “No valid DKIM records found”?
This means the tool could not find a DKIM record for the selector you entered. Either the selector is incorrect, the DKIM record is not published in your DNS, or the record is malformed. Double‑check your selector and verify that your email provider has given you the correct DKIM record to add to your DNS.

How often should I check my DKIM records?
You should check your DKIM records whenever you change email providers, rotate your DKIM keys, or update your DNS settings. Regular checks help you catch misconfigurations early.

Is this tool free to use?
Yes, this tool is completely free. There are no usage limits and you do not need to create an account.

Why Email Authentication Matters

Email authentication is not just a technical detail. It directly affects whether your messages reach the inbox or get flagged as spam. Major email providers now require proper authentication for bulk senders. Without DKIM, SPF, and DMARC, your emails are more likely to be rejected or sent to the spam folder.

DKIM adds a layer of trust. When a receiving server verifies your DKIM signature, it knows the email was not altered in transit and that it came from your domain. This builds reputation over time and helps your legitimate emails get delivered reliably.

Get Started Now

Enter your domain and selector above and run your first DKIM check. The tool gives you instant feedback on your email authentication setup. If you find issues, the recommendations section tells you exactly what to fix.

For a deeper understanding of DKIM, you can read the official specification in RFC 6376, which defines the format and rules for DKIM signatures and records. You can also learn more about email authentication and how DKIM fits into the broader landscape of email security.

Check your DKIM records today and make sure your emails are authenticated and trusted.

Disclaimer: Results from this tool are provided for informational purposes only. While we strive for accuracy, we cannot guarantee that every result is complete or error-free. Always verify important findings using additional methods before making security, technical, or business decisions.